Tracking over many frames
So far we’ve
only considered two frames
Basic
extension to f frames
1.Select features in first frame
2.Given feature in frame i, compute position/deformation
in i+1
3.Select more features if needed
4.i = i + 1
5.If i < f, go to step 2
Issues
•Discrete
search vs. Lucas Kanade?
–depends
on expected magnitude of motion
–discrete
search is more flexible
•How
often to update feature template?
–update
often enough to compensate for distortion
–updating
too often causes drift
•How
big should search window be?
–too
small: lost features. Too large:
slow